In applications, such as biological sensor implants and mobile communications devices, it is desirable to have antennas that work equally well in all directions, regardless of the orientation of the antenna. For some applications, millimeter scale antenna structures suitable for use at frequencies of 2.4 GHz, 5 GHz, and 60 GHz are desirable. Planar antennas of millimeter scale can be formed on a substrate. However, to achieve orientation-independent omnidirectionality, three dimensional antenna structures are desirable. Another reason that three dimensional antenna structures are desirable is to reduce the effects of interference from integrated circuits located on a substrate near an antenna structure.
One possible method of fabricating millimeter scale three dimensional antennas is to form the antennas on a flexible planar substrate and then bend the substrate to form a three dimensional antenna structure. One problem with this approach is that flexible substrates have a minimum bending radius of much larger than one millimeter and can thus not easily be used to form three dimensional antenna structures.
Accordingly, there exists a need for methods for forming millimeter scale three dimensional antenna structures and antenna structures formed using such methods.